1. Field of the Invention
The invention pertains to optical image formation for medical purposes using echography and, more especially, to a method for generating ultrasonic images, especially images of the heart, and to the device designed to use this method.
Echography is a method for the digital formation of optical images in real time, and has many applications. However, the quality and resolution of the images obtained are affected by interference from elementary diffusers which cause a granular noise known as "speckle". This speckle disturbs the visual quality of images obtained from the ultrasonic signals received. It is, therefore, necessary to reduce speckle by enhancing the contrast in the image. Besides, it can be made easier to use of images thus obtained by introducing an automatic procedure to detect the contours of an organ, an operation which is presently performed by the operator.
2. Description of the Prior Art
The processing of ultrasonic images is a little used method to date, despite the digitalization of the images obtained. In general, simple, recursive, mean-obtaining filters are used, and they only partly get rid of speckle. In cardiac echography, for example, significant parameters are obtained with manual contour detection.
The object of the present invention is an automatic method for generating images from ultrasonic signals obtained by echography, a method through which speckle is eliminated and which can also be used to estimate the contour of an organ by an automatic dynamic procedure and to display this contour in real time by an overlay the initial image or on the noise-cleansed image.